Moving my office to the red room and refurnishing it was one of the best things I've done probably ever to really create a comfortable environment for myself. It's crazy just how much something like this can affect your mood and motivation.
The old office was much smaller, smelled like cat pee, and on the north side of the house, so it never saw direct sun. The new office is on the south side of the house with six-foot windows, is much bigger, and now has a great couch I can sink into to relax. It's also the first room I see when I come in through the garage, so that makes me happy as well.
Aside from watching some DVR'd episodes of The Daily Show while eating dinner, I haven't spent any time in my living room in probably a week or so. So now I know: If your environment isn't facilitating positive feelings, change it!